xref: /xnu-8792.61.2/libsyscall/wrappers/string/strsep.c (revision 42e220869062b56f8d7d0726fd4c88954f87902c)
1*42e22086SApple OSS Distributions /*-
2*42e22086SApple OSS Distributions  * Copyright (c) 1990, 1993
3*42e22086SApple OSS Distributions  *	The Regents of the University of California.  All rights reserved.
4*42e22086SApple OSS Distributions  *
5*42e22086SApple OSS Distributions  * Redistribution and use in source and binary forms, with or without
6*42e22086SApple OSS Distributions  * modification, are permitted provided that the following conditions
7*42e22086SApple OSS Distributions  * are met:
8*42e22086SApple OSS Distributions  * 1. Redistributions of source code must retain the above copyright
9*42e22086SApple OSS Distributions  *    notice, this list of conditions and the following disclaimer.
10*42e22086SApple OSS Distributions  * 2. Redistributions in binary form must reproduce the above copyright
11*42e22086SApple OSS Distributions  *    notice, this list of conditions and the following disclaimer in the
12*42e22086SApple OSS Distributions  *    documentation and/or other materials provided with the distribution.
13*42e22086SApple OSS Distributions  * 4. Neither the name of the University nor the names of its contributors
14*42e22086SApple OSS Distributions  *    may be used to endorse or promote products derived from this software
15*42e22086SApple OSS Distributions  *    without specific prior written permission.
16*42e22086SApple OSS Distributions  *
17*42e22086SApple OSS Distributions  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18*42e22086SApple OSS Distributions  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19*42e22086SApple OSS Distributions  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20*42e22086SApple OSS Distributions  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21*42e22086SApple OSS Distributions  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22*42e22086SApple OSS Distributions  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23*42e22086SApple OSS Distributions  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24*42e22086SApple OSS Distributions  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25*42e22086SApple OSS Distributions  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26*42e22086SApple OSS Distributions  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27*42e22086SApple OSS Distributions  * SUCH DAMAGE.
28*42e22086SApple OSS Distributions  */
29*42e22086SApple OSS Distributions 
30*42e22086SApple OSS Distributions #include "string.h"
31*42e22086SApple OSS Distributions 
32*42e22086SApple OSS Distributions /*
33*42e22086SApple OSS Distributions  * Get next token from string *stringp, where tokens are possibly-empty
34*42e22086SApple OSS Distributions  * strings separated by characters from delim.
35*42e22086SApple OSS Distributions  *
36*42e22086SApple OSS Distributions  * Writes NULs into the string at *stringp to end tokens.
37*42e22086SApple OSS Distributions  * delim need not remain constant from call to call.
38*42e22086SApple OSS Distributions  * On return, *stringp points past the last NUL written (if there might
39*42e22086SApple OSS Distributions  * be further tokens), or is NULL (if there are definitely no more tokens).
40*42e22086SApple OSS Distributions  *
41*42e22086SApple OSS Distributions  * If *stringp is NULL, strsep returns NULL.
42*42e22086SApple OSS Distributions  */
43*42e22086SApple OSS Distributions __attribute__((visibility("hidden")))
44*42e22086SApple OSS Distributions char *
strsep(char ** stringp,const char * delim)45*42e22086SApple OSS Distributions strsep(char **stringp, const char *delim)
46*42e22086SApple OSS Distributions {
47*42e22086SApple OSS Distributions 	char *s;
48*42e22086SApple OSS Distributions 	const char *spanp;
49*42e22086SApple OSS Distributions 	int c, sc;
50*42e22086SApple OSS Distributions 	char *tok;
51*42e22086SApple OSS Distributions 
52*42e22086SApple OSS Distributions 	if ((s = *stringp) == NULL) {
53*42e22086SApple OSS Distributions 		return NULL;
54*42e22086SApple OSS Distributions 	}
55*42e22086SApple OSS Distributions 	for (tok = s;;) {
56*42e22086SApple OSS Distributions 		c = *s++;
57*42e22086SApple OSS Distributions 		spanp = delim;
58*42e22086SApple OSS Distributions 		do {
59*42e22086SApple OSS Distributions 			if ((sc = *spanp++) == c) {
60*42e22086SApple OSS Distributions 				if (c == 0) {
61*42e22086SApple OSS Distributions 					s = NULL;
62*42e22086SApple OSS Distributions 				} else {
63*42e22086SApple OSS Distributions 					s[-1] = 0;
64*42e22086SApple OSS Distributions 				}
65*42e22086SApple OSS Distributions 				*stringp = s;
66*42e22086SApple OSS Distributions 				return tok;
67*42e22086SApple OSS Distributions 			}
68*42e22086SApple OSS Distributions 		} while (sc != 0);
69*42e22086SApple OSS Distributions 	}
70*42e22086SApple OSS Distributions 	/* NOTREACHED */
71*42e22086SApple OSS Distributions }
72